Liquid crystal display device

ABSTRACT

In a liquid crystal display device, a second substrate has detection electrodes of a touch panel, each of pixels has a pixel electrode and a counter electrode divided into a plurality of blocks. The counter electrodes of the respective blocks are commonly provided for the respective pixels of plural continuous display lines, the counter electrodes of the respective blocks double scanning electrodes of the touch panel, and a driver circuit that applies a counter voltage and a touch panel scanning voltage to the counter electrodes of the respective blocks is provided. The driver circuit sequentially applies the touch panel scanning voltage to the counter electrodes of the respective blocks in plural times, while a drive pulse for displaying an image on a liquid crystal display panel is not varied, and drive frequencies of the respective touch panel scanning voltages are different from each other.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority from Japanese applicationJP2012-105191 filed on May 2, 2012, the content of which is herebyincorporated by reference into this application.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid crystal display device, andmore particularly to a technique effectively applied to an in-cellliquid crystal display device with a built-in touch panel.

2. Description of the Related Art

A display device having a device (hereinafter also referred to as “touchsensor” or “touch panel”) that enters information by conducting touchoperation (touch pressing operation, hereinafter referred to simply as“touch”) on a display screen by the aid of a user's finger or a pen isused for mobile electronic devices such as a PDA or a mobile terminal, avariety of home electric appliances, and automated teller machines.

As the touch panel of this type, there has been known a capacitance typethat detects a change in capacitance of a touched portion and isdescribed, for example, in JP2011-86038. As the capacitance type touchpanel, there has been known a liquid crystal display device having aso-called in-cell type touch panel in which a touch panel function isincorporated in a liquid crystal display panel. In the in-cell typetouch panel, a counter electrode (also called “common electrode”) formedon a first substrate (so-called “TFT substrate”) configuring the liquidcrystal display panel is divided for use as scanning electrodes of thetouch panel.

SUMMARY OF THE INVENTION

In a normal touch panel, in order to lessen an influence of a noisesource of a terminal having a touch panel mounted thereon on touchdetection, a frequency for driving electrodes (scanning electrodes,detection electrodes) of the touch panel is adjusted. JP2011-86038describes such a case. On the other hand, in the in-cell type touchpanel having the touch panel function incorporated in the liquid crystaldisplay panel, in order to avoid an influence of the noise generatedfrom the liquid crystal display panel, the touch panel is scanned attiming when the liquid crystal display panel is not driven withreference to a synchronizing signal of the liquid crystal display panel.For that reason, a drive frequency of the touch panel depends on a drivefrequency of the liquid crystal display panel, and cannot be freelyadjusted.

The present invention has been made to solve the problems with therelated art, and therefore an object of the present invention is toprovide a technique in which a drive frequency of a touch panel can befreely adjusted without depending on a drive frequency of a liquidcrystal display panel in a liquid crystal display device with a built-intouch panel function.

The above and other objects and novel features of the present inventionwill become apparent from the description of the present invention andthe attached drawings.

An outline of typical features of the invention disclosed in the presentspecification will be described in brief below.

(1) According to the present invention, there is provided a liquidcrystal display device, including: a first substrate; a second substratehaving detection electrodes of a touch panel; a liquid crystal heldbetween the first substrate and the second substrate; a plurality ofpixels arrayed in a matrix, each having a pixel electrode and a counterelectrode divided into a plurality of blocks; and a driver circuit thatapplies a counter voltage and a touch panel scanning voltage to thedivided counter electrodes of the respective blocks, in which thedivided counter electrodes of the respective blocks are commonlyprovided on the respective pixels of a plurality of continuous displaylines, in which the divided counter electrodes of the respective blocksdouble as scanning electrodes of the touch panel, in which if N is aninteger of 2 or larger, the driver circuit sequentially applies thetouch panel scanning voltage to the divided counter electrodes of therespective blocks in N horizontal scanning periods while a drive pulsefor displaying an image is not varied, and in which a drive frequency ofthe touch panel scanning voltage which is applied to the divided counterelectrodes of the respective blocks in the respective periods of the Nhorizontal scanning periods is different in each of the N horizontalscanning periods.(2) There is provide the liquid crystal display device according to theitem (1), in which the first substrate includes a plurality of videolines that input a video voltage to the respective pixels, and aplurality of scanning lines that input a scanning voltage to therespective pixels, and in which a period during which the drive pulsefor displaying the image on a liquid crystal display panel is not variedis a period other than a voltage transition timing point of the videovoltage on the video lines, a rising time point of the scanning voltage,or a falling time point of the scanning voltage.(3) According to the present invention, there is provided a liquidcrystal display device, including: a first substrate; a second substratehaving detection electrodes of a touch panel; a liquid crystal heldbetween the first substrate and the second substrate; a plurality ofpixels arrayed in a matrix, each having a pixel electrode and a counterelectrode divided into a plurality of blocks; and a driver circuit thatapplies a counter voltage and a touch panel scanning voltage to thedivided counter electrodes of the respective blocks, in which thedivided counter electrodes of the respective blocks are commonlyprovided on the respective pixels of a plurality of continuous displaylines, in which the divided counter electrodes of the respective blocksdouble as scanning electrodes of the touch panel, in which, if N is aninteger of 2 or larger, the driver circuit sequentially applies thetouch panel scanning voltage to the divided counter electrodes of therespective blocks in N horizontal scanning periods while a drive pulsefor displaying an image is not varied, and in which timing at which thetouch panel scanning voltage is applied to the divided counterelectrodes of the respective blocks in the respective periods of the Nhorizontal scanning periods is different in each of the N horizontalscanning periods.(4) There is provided the liquid crystal display device according to theitem 3, in which the first substrate includes a plurality of video linesthat input a video voltage to the respective pixels, and a plurality ofscanning lines that input a scanning voltage to the respective pixels,and in which a period during which the drive pulse for displaying theimage on a liquid crystal display panel is not varied is a period otherthan a voltage transition timing point of the video voltage on the videolines, a rising time point of the scanning voltage, or a falling timepoint of the scanning voltage.(5) According to the present invention, there is provided a liquidcrystal display device, including: a first substrate; a second substratehaving detection electrodes of a touch panel; a liquid crystal heldbetween the first substrate and the second substrate; a plurality ofpixels arrayed in a matrix, each having a pixel electrode and a counterelectrode divided into a plurality of blocks; and a driver circuit thatapplies a counter voltage and a touch panel scanning voltage to thedivided counter electrodes of the respective blocks, in which thedivided counter electrodes of the respective blocks are commonlyprovided on the respective pixels of a plurality of continuous displaylines, in which the divided counter electrodes of the respective blocksdouble as scanning electrodes of the touch panel, in which if N is aninteger of 2 or larger, the driver circuit sequentially applies thetouch panel scanning voltage to the divided counter electrodes of therespective blocks in N horizontal scanning periods while a drive pulsefor displaying an image is not varied, and in which a period since areference time point till a time point when the touch panel scanningvoltage is applied to the divided counter electrodes of the respectiveblocks in the respective periods of the N horizontal scanning periods isdifferent in each of the N horizontal scanning periods.(6) There is provided the liquid crystal display device according to theitem 5, in which the first substrate includes a plurality of scanninglines that input a scanning voltage to the respective pixels, and inwhich the reference time point is one of a rising time point of thescanning voltage, and a falling time point of the scanning voltage.(7) There is provided the liquid crystal display device according to theitem 5, in which the first substrate includes a plurality of video linesthat input a video voltage to the respective pixels, and a plurality ofscanning lines that input a scanning voltage to the respective pixels,and in which a period during which the drive pulse for displaying theimage on a liquid crystal display panel is not varied is a period otherthan a voltage transition timing point of the video voltage on the videolines, a rising time point of the scanning voltage, or a falling timepoint of the scanning voltage.(8) According to the present invention, there is provided a liquidcrystal display device, including: a first substrate; a second substratehaving detection electrodes of a touch panel; a liquid crystal heldbetween the first substrate and the second substrate; a plurality ofpixels arrayed in a matrix, each having a pixel electrode and a counterelectrode divided into a plurality of blocks; and a driver circuit thatapplies a counter voltage and a touch panel scanning voltage to thedivided counter electrodes of the respective blocks, in which thedivided counter electrodes of the respective blocks are commonlyprovided on the respective pixels of a plurality of continuous displaylines, in which the divided counter electrodes of the respective blocksdouble as scanning electrodes of the touch panel, in which if N is aninteger of 2 or larger, the driver circuit sequentially applies thetouch panel scanning voltage to the divided counter electrodes of therespective blocks in N horizontal scanning periods while a drive pulsefor displaying an image on a liquid crystal display panel is not varied,and in which when it is assumed that t_txdly is a unit delay time,t_txwait is a given wait time, n is an integer of 1 or larger and Norsmaller, and delay=(n−1)×t_txdl is satisfied, the driver circuit appliesthe touch panel scanning voltage to the divided counter electrodes ofthe respective blocks after a period (t_txwait+delay) has been elapsedfrom a reference time point when applying the touch panel scanningvoltage to the divided counter electrodes of the respective blocks in ann-th horizontal scanning period.(9) There is provided the liquid crystal display device according to theitem 8, in which the first substrate includes a plurality of scanninglines that input a scanning voltage to the respective pixels, and inwhich the reference time point is one of a rising time point of thescanning voltage, and a falling time point of the scanning voltage.(10) There is provided the liquid crystal display device according tothe item 8, in which the driver circuit has a register in which the unitdelay time (t_txdly) is stored.(11) There is provided the liquid crystal display device according tothe item 8, in which when it is assumed that t_txmaxd is a maximum delaytime, if a delay time “delay” becomes t_txmaxd or larger, the delay timeof “delay” is replaced with a delay time of (delay−(n−1)×t_txdly).(12) There is provided the liquid crystal display device according tothe item 11, in which the driver circuit has a register in which themaximum delay time (t_txmaxd) is stored.(13) There is provided the liquid crystal display device according tothe item 8, in which the driver circuit includes: a sequencer; a touchpanel scanning voltage generator circuit that generates the touch panelscanning voltage under a control of the sequencer; and a delay circuitthat delays the touch panel scanning voltage output from the touch panelscanning voltage generator circuit under the control of the sequencer bya desired delay time.

Advantages obtained by typical features of the invention disclosed inthe present application are described in brief below. According to theliquid crystal display device incorporating a touch panel function ofthe present invention, the drive frequency of the touch panel can befreely adjusted without depending on the drive frequency of the liquidcrystal display panel.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view illustrating an outlineconfiguration of a liquid crystal display device with a built-in touchpanel;

FIG. 2 is a diagram illustrating counter electrode and detectionelectrodes in the liquid crystal display device with the built-in touchpanel illustrated in FIG. 1;

FIG. 3 is a schematic cross-sectional view partially enlarging across-section of a display portion in the liquid crystal display devicewith the built-in touch panel illustrated in FIG. 1;

FIG. 4 is a block diagram illustrating an overall outline configurationof the touch panel according to an embodiment of the present invention;

FIG. 5 is a diagram illustrating a detection principle of the touchpanel according to the embodiment of the present invention;

FIG. 6 is a timing chart of a touch detection operation of the touchpanel according to the embodiment of the present invention;

FIG. 7 is a diagram illustrating timing of touch panel detection andpixel writing in the liquid crystal display device with the built-intouch panel;

FIG. 8 is a timing chart of liquid crystal display panel drive andsensor electrode drive in the liquid crystal display device according tothe embodiment of the present invention;

FIG. 9 is a diagram illustrating the specification of two registersaccording to the embodiment of the present invention; and

FIG. 10 is a diagram illustrating touch panel scanning timing accordingto the embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiments of the present invention will be described indetail with reference to the attached drawings. In all of the drawingsillustrating the embodiments, parts having the same function are denotedby identical symbols, and its repetitive description will be omitted.Also, the following embodiments do not limit the interpretation of theclaims of the present invention.

FIG. 1 is an exploded perspective view illustrating an outlineconfiguration of a liquid crystal display device with a built-in touchpanel in which a touch panel is incorporated into a liquid crystaldisplay panel. As illustrated in FIG. 1, the liquid crystal displaydevice according to the embodiment of the present invention includes afirst substrate 2 (hereinafter referred to as “TFT substrate 2”), asecond substrate 3 (hereinafter referred to as “CF substrate 3”), acounter electrode 21 (also called “common electrode”), a liquid crystaldriver IC 5, a main flexible wiring substrate MFPC, a front window 40,and a connection flexible wiring substrate 53. In the liquid crystaldisplay device illustrated in FIG. 1, a rear surface side transparentconductive film (CD) on the CF substrate 3 is divided into band-likepatterns as detection electrodes 31 of the touch panel. The counterelectrode 21 formed in the interior of the TFT substrate 2 is dividedinto band-like patterns, that is, divided into a plurality of blocks todouble as scanning electrodes of the touch panel, thereby eliminating atouch panel substrate used in a normal touch panel. Also, in the liquidcrystal display device illustrated in FIG. 1, a circuit for driving thetouch panel is disposed in the interior of the liquid crystal driver IC5.

Subsequently, a description will be given of the counter electrode 21and the detection electrodes 31 in the liquid crystal display deviceillustrated in FIG. 1, with reference to FIG. 2. As described above, thecounter electrode 21 is disposed on the TFT substrate 2, and a plurality(for example, about 32) of counter electrodes 21 are commonly connectedat both ends thereof, and connected to counter electrode signal lines22. In the liquid crystal display device illustrated in FIG. 2, a bundleof the counter electrodes 21 doubles as scanning electrodes (Tx), andthe detection electrodes 31 also configure detection electrodes (Rx).Accordingly, a counter electrode signal includes a counter voltage usedfor image display, and a touch panel scanning voltage used for detectionof a touch position. When the touch panel scanning voltage is applied tothe counter electrodes 21, a detection signal is generated in thedetection electrodes 31 arranged at a given distance from the counterelectrodes 21, and configuring a capacitance. The detection signal isextracted to the external through a detection electrode terminal 36.Dummy electrodes 33 are formed on both sides of the detection electrodes31. The detection electrodes 31 form T-shaped detection electrodeterminals 36 which are widened toward the dummy electrodes 33 side, onone end thereof. Also, a variety of lines and terminals such as a drivercircuit input terminal 25 are formed on the TFT substrate 2 except forthe counter electrode signal lines 22.

FIG. 3 is a schematic cross-sectional view partially enlarging across-section of a display portion in the liquid crystal display deviceillustrated in FIG. 1. As illustrated in FIG. 3, a pixel portion 200 isformed on the TFT substrate 2, and the counter electrodes 21 are usedfor image display as a part of pixels. Also, a liquid crystalcomposition 4 is held between the TFT substrate 2 and the CF substrate3. The detection electrodes 31 formed on the CF substrate 3 and thecounter electrodes 21 formed on the TFT substrate 2 form capacitancestherebetween. When a drive signal is supplied to each of the counterelectrodes 21, a voltage across the corresponding detection electrodes31 is changed. In this situation, as illustrated in FIG. 3, when anelectric conductor such as a finger 502 comes in proximity to or incontact with the detection electrodes 31 through the front window 40, acapacitance is changed, and the voltage across the detection electrodes31 is changed as compared with a case in which there is no proximity orcontact of the electric conductor. Thus, the change in the capacitanceoccurring between the counter electrodes 21 and the detection electrodes31 formed in the liquid crystal display panel is detected, to enable thefunction of the touch panel to be provided in the liquid crystal displaypanel.

FIG. 4 is a block diagram illustrating an overall outline configurationof the touch panel according to the embodiment of the present invention.As illustrated in FIG. 4, the touch panel according to the embodiment ofthe present invention includes an LCD driver 101, a sequencer 102, atouch panel scanning voltage generator circuit 103, a delay circuit 104,a decoder circuit 106, a touch panel 107, a detector circuit 108, aregister 1051, and a register 1052. On the touch panel 107 is formed anelectrode pattern (scanning electrodes of Tx1 to Tx5, detectionelectrodes of Rx1 to Rx5) which are sensor terminals for detecting touchby a user. In this embodiment, because of an in-cell type touch panel inwhich the touch panel function is incorporated into the liquid crystaldisplay panel, the bundle of counter electrodes 21 illustrated in FIG. 2double the scanning electrodes (Tx), and the detection electrodes 31configure the detection electrodes (Rx). The LCD driver 101 transmitssynchronizing signals (a vertical synchronizing signal (Vsync) and ahorizontal synchronizing signal (Hsync)) for displaying an image on theliquid crystal display panel to the sequencer 102. The sequencer 102controls the touch panel scanning voltage generator circuit 103, thedelay circuit 104, the decoder circuit 106, and the detector circuit 108to control the timing of the touch detection operation. The touch panelscanning voltage generator circuit 103 generates and outputs a touchpanel scanning voltage (Vstc) for driving the scanning electrodes of Tx1to Tx5.

The delay circuit 104 delays the touch panel scanning voltage (Vstc)input from the touch panel scanning voltage generator circuit 103 by theamount of delay instructed from the sequencer 102. The sequencer 102determines the amount of delay on the basis of parameters stored in theregisters (1051, 1052). The register 1051 is a register that stores aunit delay time, and the register 1052 is a register that stores amaximum delay time. The unit delay time stored in the register 1051 is aunit time by which the touch panel scanning voltage (Vstc) is delayed,which is a parameter for determining a drive frequency of the touchpanel scanning voltage (Vstc). The maximum delay time stored in theregister 1052 is a maximum time by which the touch panel scanningvoltage (Vstc) is delayed, which is a parameter that defines anallowable range in which the timing of the touch panel scanning voltage(Vstc) is varied. The decoder circuit 106 is an analog switch(demultiplexer) that outputs the touch panel scanning voltage (Vstc) toone scanning electrode among the scanning electrodes of Tx1 to Tx5 onthe basis of a select signal input from the sequencer 102. The detectorcircuit 108 detects inter-electrode capacitances (mutual capacitances)at intersection points of one scanning electrode to which the touchpanel scanning voltage (Vstc) is applied among the scanning electrodesof Tx1 to Tx5, and the respective detection electrodes of Rx1 to Rx5.

FIG. 5 is a diagram illustrating a detection principle of the touchpanel according to the embodiment of the present invention. FIG. 6 is atiming chart of the touch detection operation of the touch panelaccording to the embodiment of the present invention. The sequencer 102controls the touch panel scanning voltage generator circuit 103, andsequentially applies the touch panel scanning voltage (Vstc) to thescanning electrodes of Tx1 to Tx5 in synchronization with the verticalsynchronizing signal (Vsync) and the horizontal synchronizing signal(Hsync). In this example, as illustrated in FIGS. 5 and 6, the touchpanel scanning voltage (Vstc) is applied to the respective scanningelectrodes in plural times (eight times in FIG. 6). As illustrated inFIG. 6, the detector circuit 108 integrates detection voltages developedin the respective detection electrodes of Rx1 to Rx5 together(integration in a negative direction in FIG. 6), and records an attainedvoltage value (ΔVa, ΔVb). When a neighborhood of an intersection pointbetween the scanning electrode (Tx) and the detection electrode (Rx) istouched with the finger (conductor), because a current also flows intothe finger, a voltage value of the integration result is changed. Forexample, in FIG. 6, because no finger is present in the vicinity of theintersection point between the scanning electrode (Tx1) and a detectionelectrode (R×N) (a non-touch state indicated by NA in FIG. 6), a voltageobtained by integrating the detection voltages together becomes anon-touch level (LA). On the contrary, because the finger is present inthe vicinity of the intersection point between the scanning electrode(Tx2) and the detection electrode (R×N) (a touch state indicated by NBin FIG. 6), the current also flows into the finger, and a voltageobtained by integrating the detection voltages together becomes avoltage of higher potential than that in the non-touch level (LA). Thetouch position can be detected according to the amount of change (touchsignal).

FIG. 7 is a diagram illustrating timing of touch panel detection andpixel writing in the liquid crystal display device with the built-intouch panel. Referring to FIG. 7, T3 is a flyback period, VSYNC is thevertical synchronizing signal, and HSYNC is the horizontal synchronizingsignal. Symbol A in FIG. 7 indicates pixel write timing from a firstdisplay line to 1280th display line in a pixel write period (T4) of oneframe, and symbol B in FIG. 7B indicates touch panel detection timing inthe counter electrodes (CT1 to CT20) of the respective blocks dividedinto 20 blocks. As illustrated in FIG. 7, the counter electrode of anarbitrary display line is allowed to function as the scanning electrode(Tx), and the scanning operation at the time of the touch paneldetection is conducted at a location different from that in which gatescan for writing the pixel is conducted. As illustrated in FIG. 7, thegate scan and the touch panel scan are implemented on different displaylines. However, because parasitic capacitances are present between eachvideo line and the counter electrode (CT), and between each scanningline and the counter electrode (CT), a detection sensitivity at the timeof the touch panel detection is lessened by a variation in a voltage(VDL) on the video line, or noise occurring at the time of rising orfalling of a scanning voltage (VGL). Under the circumstances, in thisembodiment, the touch position detection operation is executed in aperiod when there is no variation in the voltage (VDL) on the videoline, or there is no rising or falling of the scanning voltage (VGL).

FIG. 8 is a timing chart of the liquid crystal display panel drive andthe sensor electrode drive in the liquid crystal display deviceaccording to the embodiment of the present invention. Referring to FIG.8, VGL is the scanning voltage on the scanning line, VDL is the videovoltage on the video line, Vcom is a counter voltage (also called“common voltage”) which is applied to the counter electrode, Vstc is thetouch panel scanning voltage, 1H is one horizontal scanning period, andTxs is a touch panel scanning start wait period. In the liquid crystaldisplay device according to this embodiment, since dot inversion isapplied as an AC drive method, the counter voltage is a voltage of Vcomhaving a given potential. In the in-cell type touch panel in which thetouch panel function is incorporated into the liquid crystal displaypanel, because the bundle of counter electrodes 21 illustrated in FIG. 2also operates as the scanning electrode (Tx) for touch detection, thedisplay operation (A in FIG. 8) of the liquid crystal display panel andthe touch position detection operation (B in FIG. 8) are completelytime-shared, and a synchronization control needs to be conducted. Asdescribed above, in this embodiment, the touch position detectionoperation is executed in a period (a period of TA or a period of TB inFIG. 8) when there is no variation in the voltage (VDL) on the videoline, or there is no rising or falling of the scanning voltage (VGL).

FIG. 9 is a diagram illustrating the specification of the register 1051and the register 1052 according to the embodiment of the presentinvention. A register whose register name illustrated in FIG. 9 is“TCP_TXDLY” is the register 1051 illustrated in FIG. 4, in which theparameter is “unit delay time (t_txdly)”, and the unit delay time is set0 to 18.0 us at intervals of 0.286 us. Also, a register of “TCP_TXMAXD”illustrated in FIG. 9 is the register 1052 illustrated in FIG. 4, inwhich the parameter is “maximum delay time (t_txmaxd)”, and the maximumdelay time is set 0 to 18.0 us at intervals of 0.286 us. In this case, acondition of t_txdly<t_txmaxd needs to be satisfied.

FIG. 10 is a diagram illustrating the touch panel scanning timingaccording to the embodiment of the present invention. Referring to FIG.10, 1H is one horizontal scanning period, and TxH is a touch panelscanning period. In this embodiment, when the touch panel scanningvoltage (Vstc) is applied to the same scanning electrode (Tx) over aplurality of horizontal scanning periods in plural times (for example,32 times), timing at which the touch panel scanning voltage (Vstc) isapplied to the scanning electrode (Tx) is delayed by the unit delay timestored in the register 1051 every one horizontal scanning period. Thedelay time does not exceed the maximum delay time stored in the register1052.

In this embodiment, as illustrated in FIG. 10, in a first horizontalscanning period, the timing at which the touch panel scanning voltage(Vstc) is applied to the scanning electrode (Tx), is a time point aftera given wait time (t_txwait) has been elapsed from a rising time pointof the horizontal synchronizing signal (Hsync). In a second horizontalscanning period, the timing at which the touch panel scanning voltage(Vstc) is applied to the scanning electrode (Tx), is a time point(t_txwait+t_txdly) after a period obtained by adding the unit delay time(t_txdly) to the given wait time (t_txwait) has been elapsed from therising time point of the horizontal synchronizing signal (Hsync). In ann-th (0≦n≦31) horizontal scanning period, the timing at which the touchpanel scanning voltage (Vstc) is applied to the scanning electrode (Tx),is a time point (t_txwait+nxt_txdly) after a period obtained by addingan n×unit delay time (nxt_txdly) to the given wait time (t_txwait) hasbeen elapsed from the rising time point of the horizontal synchronizingsignal (Hsync). Thus, in this embodiment, when the touch panel scanningvoltage (Vstc) is applied to the same scanning electrode (Tx) over aplurality of horizontal scanning periods in plural times (for example,32 times), timing at which the touch panel scanning voltage (Vstc) isapplied to the scanning electrode (Tx) in the n-th (0≦n≦31) horizontalscanning period is represented by (t_txwait+delay; delay=nxt_txdly).Then, when (nxt_txdly) is equal to or larger than the maximum delay time(t_txmaxd) (n×t_txdly≧t_txmaxd), the timing is represented by(delay=delay−n×t_txdly).

Hereinafter, an setting example of the register (TPC_TXDLY) 1051 andregister (TPC_TXMAXD) 1052 will be described.

If touch panel scanning period (T×H)>one horizontal scanning period(1H),

(Example 1) register (TPC_TXDLY)=1, and register (TPC_TXMAXD)=5 Thenumber of delays=0, 1, 2, 3, 4, 0, 1, . . .(Example 2) register (TPC_TXDLY)=2, and register (TPC_TXMAXD)=5 Thenumber of delays=0, 2, 4, 1, 3, 0, 2, . . .

If touch panel scanning period (T×H)<one horizontal scanning period(1H),

(Example 3) register (TPC_TXDLY)=9, and register (TPC_TXMAXD)=10 Thenumber of delays=0, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 9, . . .

While there have been described what are at present considered to becertain embodiments of the invention, it will be understood that variousmodifications may be made thereto, and it is intended that the appendedclaim cover all such modifications as fall within the true spirit andscope of the invention.

What is claimed is:
 1. A liquid crystal display device, comprising: afirst substrate; a second substrate having detection electrodes of atouch panel; a liquid crystal held between the first substrate and thesecond substrate; a plurality of pixels arrayed in a matrix, each havinga pixel electrode and a counter electrode divided into a plurality ofblocks; and a driver circuit that applies a counter voltage and a touchpanel scanning voltage to the divided counter electrodes of therespective blocks, wherein the divided counter electrodes of therespective blocks are commonly provided on the respective pixels of aplurality of continuous display lines, wherein the divided counterelectrodes of the respective blocks double as scanning electrodes of thetouch panel, wherein, if N is an integer of 2 or larger, the drivercircuit sequentially applies the touch panel scanning voltage to thedivided counter electrodes of the respective blocks in N horizontalscanning periods while a drive pulse for displaying an image is notvaried, and wherein a drive frequency of the touch panel scanningvoltage which is applied to the divided counter electrodes of therespective blocks in the respective periods of the N horizontal scanningperiods is different in each of the N horizontal scanning periods. 2.The liquid crystal display device according to claim 1, wherein thefirst substrate includes a plurality of video lines that input a videovoltage to the respective pixels, and a plurality of scanning lines thatinput a scanning voltage to the respective pixels, and wherein a periodduring which the drive pulse for displaying the image on a liquidcrystal display panel is not varied is a period other than a voltagetransition timing point of the video voltage on the video lines, arising time point of the scanning voltage, or a falling time point ofthe scanning voltage.
 3. A liquid crystal display device, comprising: afirst substrate; a second substrate having detection electrodes of atouch panel; a liquid crystal held between the first substrate and thesecond substrate; a plurality of pixels arrayed in a matrix, each havinga pixel electrode and a counter electrode divided into a plurality ofblocks; and a driver circuit that applies a counter voltage and a touchpanel scanning voltage to the divided counter electrodes of therespective blocks, wherein the divided counter electrodes of therespective blocks are commonly provided on the respective pixels of aplurality of continuous display lines, wherein the divided counterelectrodes of the respective blocks double as scanning electrodes of thetouch panel, wherein, if N is an integer of 2 or larger, the drivercircuit sequentially applies the touch panel scanning voltage to thedivided counter electrodes of the respective blocks in N horizontalscanning periods while a drive pulse for displaying an image is notvaried, and wherein timing at which the touch panel scanning voltage isapplied to the divided counter electrodes of the respective blocks inthe respective periods of the N horizontal scanning periods is differentin each of the N horizontal scanning periods.
 4. The liquid crystaldisplay device according to claim 3, wherein the first substrateincludes a plurality of video lines that input a video voltage to therespective pixels, and a plurality of scanning lines that input ascanning voltage to the respective pixels, and wherein a period duringwhich the drive pulse for displaying the image on a liquid crystaldisplay panel is not varied is a period other than a voltage transitiontiming point of the video voltage on the video lines, a rising timepoint of the scanning voltage, or a falling time point of the scanningvoltage.
 5. A liquid crystal display device, comprising: a firstsubstrate; a second substrate having detection electrodes of a touchpanel; a liquid crystal held between the first substrate and the secondsubstrate; a plurality of pixels arrayed in a matrix, each having apixel electrode and a counter electrode divided into a plurality ofblocks; and a driver circuit that applies a counter voltage and a touchpanel scanning voltage to the divided counter electrodes of therespective blocks, wherein the divided counter electrodes of therespective blocks are commonly provided on the respective pixels of aplurality of continuous display lines, wherein the divided counterelectrodes of the respective blocks double as scanning electrodes of thetouch panel, wherein, if N is an integer of 2 or larger, the drivercircuit sequentially applies the touch panel scanning voltage to thedivided counter electrodes of the respective blocks in N horizontalscanning periods while a drive pulse for displaying an image is notvaried, and wherein a period since a reference time point till a timepoint when the touch panel scanning voltage is applied to the dividedcounter electrodes of the respective blocks in the respective periods ofthe N horizontal scanning periods is different in each of the Nhorizontal scanning periods.
 6. The liquid crystal display deviceaccording to claim 5, wherein the first substrate includes a pluralityof scanning lines that input a scanning voltage to the respectivepixels, and wherein the reference time point is one of a rising timepoint of the scanning voltage, and a falling time point of the scanningvoltage.
 7. The liquid crystal display device according to claim 5,wherein the first substrate includes a plurality of video lines thatinput a video voltage to the respective pixels, and a plurality ofscanning lines that input a scanning voltage to the respective pixels,and wherein a period during which the drive pulse for displaying theimage on a liquid crystal display panel is not varied is a period otherthan a voltage transition timing point of the video voltage on the videolines, a rising time point of the scanning voltage, or a falling timepoint of the scanning voltage.
 8. A liquid crystal display device,comprising: a first substrate; a second substrate having detectionelectrodes of a touch panel; a liquid crystal held between the firstsubstrate and the second substrate; a plurality of pixels arrayed in amatrix, each having a pixel electrode and a counter electrode dividedinto a plurality of blocks; and a driver circuit that applies a countervoltage and a touch panel scanning voltage to the divided counterelectrodes of the respective blocks, wherein the divided counterelectrodes of the respective blocks are commonly provided on therespective pixels of a plurality of continuous display lines, whereinthe divided counter electrodes of the respective blocks double asscanning electrodes of the touch panel, wherein, if N is an integer of 2or larger, the driver circuit sequentially applies the touch panelscanning voltage to the divided counter electrodes of the respectiveblocks in N horizontal scanning periods while a drive pulse fordisplaying an image on a liquid crystal display panel is not varied, andwherein when it is assumed that t_txdly is a unit delay time, t_txwaitis a given wait time, n is an integer of 1 or larger and N or smaller,and delay=(n−1)×t_txdl is satisfied, the driver circuit applies thetouch panel scanning voltage to the divided counter electrodes of therespective blocks after a period (t_txwait+delay) has been elapsed froma reference time point when applying the touch panel scanning voltage tothe divided counter electrodes of the respective blocks in an n-thhorizontal scanning period.
 9. The liquid crystal display deviceaccording to claim 8, wherein the first substrate includes a pluralityof scanning lines that input a scanning voltage to the respectivepixels, and wherein the reference time point is one of a rising timepoint of the scanning voltage, and a falling time point of the scanningvoltage.
 10. The liquid crystal display device according to claim 8,wherein the driver circuit has a register in which the unit delay time(t_txdly) is stored.
 11. The liquid crystal display device according toclaim 8, wherein when it is assumed that t_txmaxd is a maximum delaytime, if a delay time “delay” becomes t_txmaxd or larger, the delay timeof “delay” is replaced with a delay time of (delay−(n−1)×t_txdly). 12.The liquid crystal display device according to claim 11, wherein thedriver circuit has a register in which the maximum delay time (t_txmaxd)is stored.
 13. The liquid crystal display device according to claim 8,wherein the driver circuit includes: a sequencer; a touch panel scanningvoltage generator circuit that generates the touch panel scanningvoltage under a control of the sequencer; and a delay circuit thatdelays the touch panel scanning voltage output from the touch panelscanning voltage generator circuit under the control of the sequencer bya desired delay time.